The cutting assemblies of the known large headers of plant-cutting machines may be supported by headers utilizing different operating modes, depending upon the crop being harvested. For certain crops, such as wheat or barley, the cutting assembly may be positioned approximately 6 inches above the ground during harvesting, such as by a combine. While harvesting such crops, the combine header may utilize an operating mode commonly referred to as rigid mode, since the cutter assembly would be maintained in a rigid position at all times during harvesting. In contrast, other crops, such as soybeans, require the cutting assembly to be positioned approximately 1-2 inches above the ground during harvesting. While operating the combine header in rigid mode typically maximizes the amount of crop harvested, the combine head is susceptible to damage due to encountering ground undulations in the field. Due to the possibility of such operating conditions, the combine may utilize a flex operating mode, in which individualized arms that support a small portion of the cutter assembly are movable in response to encountering ground undulations. Although utilizing a flex operating mode better protects the cutting assembly, harvesting efficiency may be reduced. However, in conventional combine constructions, by utilizing a rigid operating mode, an operator must manually adjust, typically by raising and tilting the entire header, in order to avoid damage from ground undulations. Requiring manual adjustment places additional burdens on the combine operator, leading to fatigue and other undesirable results.
What is needed is a control system that provides automatic control of the header position (vertical and/or rotational movement of the header) while the header utilizes a rigid operating mode.